WO2023244155A1

WO2023244155A1 - Handling of tracking/ran area change of mobile iab node

Info

Publication number: WO2023244155A1
Application number: PCT/SE2023/050580
Authority: WO
Inventors: Antonino ORSINO; Ritesh SHREEVASTAV; Paul Schliwa-Bertling
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-06-17
Filing date: 2023-06-09
Publication date: 2023-12-21

Abstract

According to an aspect, there is provided a method performed by a user equipment, UE. The method comprises receiving (501), from a vehicle-mounted network node that is serving the UE, one or more area codes. Another aspect provides a method performed by a first network node that is configured to provide wireless access to a communication network for one or more UEs and that is configured to have a wireless backhaul connection to the communication network via another network node. The method comprises receiving (601) one or more area codes, wherein the one or more area codes are for a second network node in the communication network that the first network node has, or will have, a wireless backhaul connection to.

Description

Handling of tracking/RAN area change of mobile IAB node

TECHNCAL FIELD

This disclosure relates to vehicle-mounted network nodes in a communication network.

BACKGROUND

Fifth Generation (5G) networks are being designed and deployed comprising a dense deployment of small cells in order to simultaneously serve more User Equipment (UEs) with higher throughput and lower delay. However, building a completely new infrastructure is costly and takes time. Deploying a wireless backhaul is envisioned to be an economically and technically viable approach to enable flexible and dense networks.

This solution was standardised in the Third Generation Partnership Project (3GPP) Release 16, under the term "Integrated Access and Backhaul” (IAB), to support wireless relaying in Next Generation-Radio Access Networks (NG- RAN), and it has continued in Release 17.

IAB Architecture

IAB is based on the Central Unit-Distributed Unit (CU-DU) split that was standardised in Release 15. The centralised unit (CU) is in charge of the radio resource control (RRC) protocol and the packet data convergence protocol (PDCP), whereas the distributed unit (DU) is in charge of the radio link control (RLC) protocol and medium access control (MAC) protocol. The F1 interface connects the CU and the DU. The CU-DU split facilitates physically separate CUs and DUs, while also allowing a single CU to be connected to multiple DUs. Fig. 1 shows the basic architecture (main components) of IAB.

Thus, Fig. 1 shows a single IAB donor connected to the core network (CN). The IAB donor serves three direct IAB child nodes through two collocated DUs at the donor for wireless backhauling. The centre IAB node in turn serves two IAB nodes through wireless backhaul. All IAB nodes in Fig. 1 backhaul traffic related to UEs connected to it, and other backhaul traffic from downstream IAB nodes.

The main components of the IAB architecture are:

1) IAB Node: A node that allows wireless access to the User Equipments (UEs) while also backhauling the traffic to other nodes. The IAB node consists of a DU that provides access to connected UEs. The node also consists of a mobile termination (MT) that connects to other IAB nodes or donors in the uplink (UL) direction for backhaul.

2) IAB Donor: A node that provides UEs an interface to the core network and wireless functionality to other IAB- nodes to backhaul their traffic to the core network.

The defining feature of IAB is the use of wireless spectrum for both access of UEs and backhauling of data through IAB donors. Thus, there needs to be clear separation of access and backhaul resources to avoid interference between them. This separation of access and backhaul resources cannot be handled during network planning due to the dynamic nature of I AB.

In Release 16, 1 AB was standardised with basic support for multi-hop multi-path backhaul for Directed Acyclic Graph (DAG) topology, and no mesh-based topology was supported. Release 16 also supports Quality of Service (QoS) prioritisation of backhaul traffic and flexible resource usage between access and backhaul. Current discussions in Release 17 are on topology enhancements for I AB with partial migration of I AB nodes for Radio Link Failure (RLF) recovery and load balancing.

Further information about the already-standardised IAB work can be found in "On Integrated Access and Backhaul Networks: Current Status and Potentials” by Madapatha, Charitha et al., in IEEE Open Journal of the Communications Society 1 (2020): 1374-1389; 3GPP TS 38.300 v17.0.0, Section 4.7 and 3GPP TR 38.874 v16.0.0 "Study on IAB”.

In Release 18, it is expected that the different Radio Access Network (RAN) groups will work towards enhancing functionality of IAB through:

• focus on mobile-IAB/vehicle mounted relays (VMR) providing 5G coverage enhancement to onboard and surrounding UEs; and

• smart repeaters that build on Long Term Evolution (LTE)-repeaters.

The initial use cases for mobile-IABA/MR are expected to be based on 3GPP TR 22.839 v18.1 .0.

One of the main use cases of a mobile IAB cell is to serve the UEs which are residing in the vehicle with the vehicle mounted relay; and integrated access backhaul solutions. Other relevant use cases for mobile lABs involve a mobile/nomadic IAB network node mounted on a vehicle that provides extended coverage. This involves scenarios where additional coverage is required during special events like concerts, or during disasters. The nomadic IAB node provides access to surrounding UEs while the backhaul traffic from the nomadic IAB node is then transmitted wirelessly, either with the help of IAB donors, or Non-terrestrial networks (NTN). A nomadic IAB node also reduces or even eliminates signal strength loss due to vehicle penetration for UEs that are present in the vehicles.

Advantages of Mobile IAB include a reduction or elimination of vehicle penetration loss (especially at high frequency), and a reduction or elimination of group handover

F1 interface

The F1 interface connects the CU to the DU in the split architecture that is also applicable to the IAB architecture. The F1 interface connects the CU from an IAB donor to IAB DU in the child IAB nodes. The F1 interface also supports control and user plane separation through F1-C and F1-U respectively.

This interface holds even during IAB mobility where an IAB node moves and connects to parent/donor IAB nodes. In such a scenario the DU present in the mobile IAB node connects to the CU present in the IAB donor.

The IAB-DU initiates a F1 setup with the IAB-CU with which it has a Transport Network Layer (TNL) connection and the initial F1 setup [as described in section 8.5 of 3GPP TS 38.401 v17.0.0]. Once the F1 setup is completed, the IAB donor CU sends a GNB-CU CONFIGURATION UPDATE to optionally indicate the DU cells to be activated.

Mobile IAB

Consider that most use cases of mobile IAB are expected to be mounted on public transport vehicles and to move, to a large extent, along a pre-determined route. Fig. 2 shows one such mobile IAB mounted on a bus travelling on a route that is covered by four different parent IAB nodes (Parent 1 , 2, 3, 4). The parent nodes backhaul their traffic through two donor nodes (Donor X, Y).

Thus, Fig. 2 shows a mobile IAB Node which involves Intra-Donor, Inter-Donor (same CU) and Inter CUs.

An IAB node has a DU that provides access to UEs around it and a Mobile Termination (MT) that provides a backhaul connection of the IAB node to its parent(s) and the rest of the network. The parent IAB nodes consist of DUs that provide access to UEs and the mobile IAB present in their coverage. They also consist of MTs that backhaul their traffic together with traffic from the mobile IAB node. Finally, the two donor nodes consist of DU that provides access and CU that is connected to the core network. The CUs in both donor nodes maintain a F1 connection to parent nodes under it.

The mobile IAB node maintains an F1 connection to the donor (one donor at a time). In Fig. 2, the mobile IAB connects to the following nodes in the different positions as described below:

1. Position A: Backhaul (BH) through Parent node 1 , F1 connection to Donor node X;

2. Position B: BH through Parent node 2, F1 connection to Donor node X;

3. Position C: BH through Parent node 3, F1 connection to Donor node Y;

4. Position D: BH through Parent node 4, F1 connection to Donor node Y.

The mobile IAB must change the F1 connection from Donor X to Donor Y when moving from position B to C, thus requiring a F1 handover and setup of backhaul RLC channels.

Tracking Area and RAN Area

In order to facilitate mobility in RRC Inactive and RRC idle; a Tracking Area and RAN Area are defined.

The Tracking Area Identity (TAI) is used to identify tracking areas. The TAI is constructed from the Public Land Mobile Network (PLMN) identity the tracking area belongs to, and the TAG (Tracking Area Code) of the Tracking Area. The Tracking Area Code and a RAN Area code (RANAC) are described in 3GPP TS 38.331 v17.0.0

Tracking Area Code

The IE Tracking AreaCode is used to identify a tracking area within the scope of a PLMN/SNPN, see TS 24.501 [23],

TrackingAreaCode information element

RAN-AreaCode

The IE RAN-AreaCode is used to identify a RAN area within the scope of a tracking area.

RAN-AreaCode information element

In the above, IE refers to an "Information Element” and "SNPN” refers to "Standalone Non-Public Network”.

A UE is provided with (at least one) RAN area identity (ID), where a RAN area is a subset of a Core Network (CN) Tracking Area, or is equal to a CN Tracking Area. A RAN area is specified by one RAN area identity (ID), which consists of a TAG and optionally a RAN Area Code.

The UE performs a RAN-based notification area update (RNAU) periodically or when the UE selects a cell that does not belong to the configured RAN Notification Area (RNA).

SUMMARY

There currently exist certain challenge(s). The Release 18 mobile I AB Work Item (Wl) will address the following objectives (as set out in RP-213601 : New WID on Mobile IAB by Qualcomm, 3GPP TSG RAN Meeting #94e, December 6-17 2021):

In the above, PCI refers to "Physical Cell ID”, RACH refers to "Random Access Channel”, RF refers to "Radio Frequency” and RRM refers to "Radio Resource Management”.

One of the main objectives is related to enhancements of aspects related to group mobility. According to this, when a mobile IAB is moving, it is possible that the mobile IAB changes its parent IAB node, and, as a consequence, the tracking area or RAN area in which the mobile IAB is located also changes. If the legacy principles are applied, the tracking area or RAN area of a network node never changes since the network node is static. Considering this, there are multiple problems that need to be solved:

1 . What is a tracking area (TA) for mobile cells? Until now, the TA is defined based on cells which are in fixed locations/positions for terrestrial networks. Even for non-terrestrial networks, the Tracking Area corresponds to a fixed geographical area. Therefore how to define TA for mobile cells without complicating the procedures is a challenge. The same tracking area issue is also applicable to the RAN area.

2. How the change in tracking area or RAN area is handled at the mobile IAB?

3. When the tracking area or RAN area of the mobile IAB changes, this will trigger a tracking area or RAN area update procedure to all the UEs under the coverage or the mobile IAB (and that are not in RRC_CONNECTED), and this may cause interference and an increased number of radio link failures (RLFs) since multiple UEs will try to access the network at the same time. Thus a problem to be solved is how to avoid this interference and increased number of radio link failures.

Certain aspects of the disclosure and their embodiments may provide solutions to one or more of these problems or other challenges. The methods and solutions proposed herein aim to provide solutions in order to handle the change of tracking area and/or RAN area by the mobile IAB. In order to do so, at least one (or a combination) of the following options can be adopted:

• When a mobile IAB changes its parent IAB node, but remains connected to the same CU (i.e. , positions A -> B and positions C -> D of Fig. 2), the mobile IAB acquires the tracking area code (TAG) and/or new RAN area code (RANAC) from either the source or target parent IAB node when performing the switching. o The acquisition by the mobile IAB of the tracking area code and/or RAN area code from the new parent IAB node may be performed by:

■ the mobile IAB-MT acquiring the tracking area code and/or RAN area code via reading the Master Information Block (MIB) or System Information Block 1 (SIB1 ) broadcast by the new parent IAB node;

■ the mobile IAB-MT acquiring the tracking area code and/or RAN area code by requesting it directly from the new parent IAB node when switching from an old parent IAB node to a new parent IAB node;

■ in the case of RAN sharing (Multi-Operator Core Network (MOON)), and when multiple PLMN IDs with distinct TAG values are broadcast, the IAB-MT selects the TAG associated with its registered PLMN;

■ after acquiring the TAG or RAN area code, the Mobile IAB-MT provides the tracking area code and/or RAN area code to the Mobile IAB-DU. The Mobile IAB-DU compares the current TAG with the one provided from the Mobile IAB-MT, and if they are different; the DU updates the System Information Block (SIB) to reflect the new tracking area code and/or RAN area code. o The mobile IAB can be configured with a range of tracking area codes and/or RAN area codes to be used when connecting to a certain parent IAB node. The mapping between the tracking area code and/or RAN area code and the parent IAB may be provided by the serving CU or by the core network when establishing the F1 and NG interface.

■ In this solution, if the mapping is configured by the current donor CU, it may be implied that some level of coordination is needed between all the CUs that will be traversed by the vehicle in which the mobile IAB is mounted;

■ The mapping can also be known (since the mobility of the mobile IAB can be considered deterministic) and thus this mapping can be provided by Operations, Administration and Maintenance (OAM). o A dedicated tracking area and/or RAN area code or a list of tracking areas and/or RAN area codes (different from the legacy one used by the parent IAB node or donor IAB node) is configured for the mobile IAB. The dedicated tracking area and/or RAN area code for the mobile IAB may cover an area that is larger than that of the parent IAB node to which the mobile IAB is currently connected. Further, in another alternative, the dedicated tracking area and/or RAN area code for the mobile IAB may cover an area that is as large as the overall area in which the vehicle (in which the mobile IAB is mounted) will travel. This area may include several parent IAB nodes but also several donor IAB nodes. ■ In case that a new TAG is configured in cells, the mobile IAB-DU must update the serving CU so that potential updates of the Access and Mobility Function (AMF) about gNB configuration can be conducted.

• The mobile IAB, after acquiring a new tracking area and/or RAN area code, can share it with the UEs under its coverage (or inside the vehicle in which the mobile IAB is mounted). When doing this, the mobile IAB may send an indication about whether the UEs under the mobile IAB should perform the tracking area and/or RAN area update procedure or not. o An alternative is that a UE, when receiving a new tracking area and/or RAN area from the same mobile IAB (meaning the mobile IAB has not changed), does not trigger any tracking area or RAN area update procedure until the UE leaves the vehicle in which the mobile IAB is mounted. o Another alternative is that the UE performing the tracking area and/or RAN area update procedure receives a tracking area or RAN area code (in SIB or via dedicated RRC signalling) that is not in the list of preconfigured tracking areas and/or RAN areas received previously by the mobile IAB.

Thus, the present disclosure provides a method performed by a mobile IAB-MT to acquire the SIBs from its serving cell and extract the TAG, RAN Area Code and inform the mobile IAB-DU of these codes. The mobile IAB-DU can verify/check if there is a change in TAG or RAN Area. If there is any change, the SIB content of mobile IAB-DU cells can be populated/updated with the new values.

More generally, this disclosure provides the following aspects that address one or more of the problems described herein.

According to a first aspect, there is provided a method performed by a UE. The method comprises receiving, from a vehicle-mounted network node that is serving the UE, one or more area codes.

According to a second aspect, there is provided a method performed by a first network node that is configured to provide wireless access to a communication network for one or more UEs, and that is configured to have a wireless backhaul connection to the communication network via another network node. The method comprises receiving one or more area codes, wherein the one or more area codes are for a second network node in the communication network that the first network node has, or will have, a wireless backhaul connection to.

According to a third aspect, there is provided a computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform the method according to the first aspect, the second aspect, or any embodiments thereof.

According to a fourth aspect, there is provided a UE configured to perform the method according to the first aspect or any embodiment thereof.

According to a fifth aspect, there is provided a UE that comprises a processor and a memory, said memory containing instructions executable by said processor whereby said UE is operative to perform the method according to the first aspect or any embodiment thereof. According to a sixth aspect, there is provided a first network node that is configured to perform the method of according to the second aspect or any embodiment thereof.

According to a seventh aspect, there is provided a first network node comprising a processor and a memory, said memory containing instructions executable by said processor whereby said first network node is operative to perform the method according to the second aspect or any embodiment thereof.

Certain embodiments may provide one or more of the following technical advantage(s). The methods and solutions proposed herein aim to handle the change of tracking area and/or RAN area by the mobile IAB. This will enable the mobile IAB to be associated with the right tracking area and/or RAN area code and, at the same time, provide that the dynamic change of this tracking area and/or RAN area code has a low impact on the UEs served by the mobile IAB.

The methods and solutions can avoid UEs served by the mobile IAB from triggering frequent tracking area and/or RAN area update procedures, thus decreasing the network load, congestion, and signalling overhead, and also increasing the battery life of the UEs.

BRIEF DESCRIPTION OF THE DRAWINGS

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings, in which:

Fig. 1 shows a basic architecture of IAB;

Fig. 2 shows a mobile IAB node mounted on a bus travelling along a route covered by four different parent IAB nodes;

Fig. 3 shows the signalling between a UE, a mobile IAB node, a Serving Cell and a Target Cell;

Fig. 4 illustrates a change in Tracking Area for a mobile IAB node;

Fig. 5 is a flow chart illustrating a method of operating a UE in accordance with some embodiments;

Fig. 6 is a flow chart illustrating a method of operating a first network node in accordance with some embodiments;

Fig. 7 shows an example of a communication system in accordance with some embodiments;

Fig. 8 shows a UE in accordance with some embodiments;

Fig. 9 shows a RAN network node in accordance with some embodiments;

Fig. 10 is a block diagram illustrating a virtualization environment in which functions implemented by some embodiments may be virtualized; and

Fig. 11 shows a communication diagram of a host communicating via a network node with a UE over a partially wireless connection in accordance with some embodiments.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

The present disclosure relates to a scenario where a mobile I AB node is mounted in a vehicle (e.g. on the inside or on the outside of the vehicle). In this scenario, one or several UEs should connect to the mobile I AB, but only when located inside the vehicle (e.g. a bus). Since the mobile IAB node (mlAB) is moving, it may traverse different tracking areas and/or RAN areas, and thus the identifiers and/or codes associated with those areas will change.

It should be noted that the terms “m-IAB”, "mobile IAB”, "mobile IAB node”, “mlAB”, and “m-IAB node” are used interchangeably.

It should also be noted that the terminology "UE connected to a mobile IAB” refers to a UE that is physically inside the vehicle in or on which the mobile IAB node is mounted.

Finally, it should also be noted that the described techniques are applicable to both or either of the "tracking area” and "RAN area”, and thus the methods/techniques are described below with reference to the general term "area”, with "area” being understood to refer to "tracking area” (applicable for RRC Idle mode) or "RAN area” (applicable for RRC Inactive mode).

As noted above, the present disclosure provides a method performed by a network node, for example a mobile IAB-MT, to acquire the SIBs from its serving cell and extract an area code such as the TAG and/or RAN Area Code (RANAC), and to inform another network node, for example a mobile IAB-DU, of this/these code(s). The network node (e.g. mobile IAB-DU) can verify/check if there is a change in TAG or RAN Area code. If there is any change, the SIB content of cells of the network node (e.g. mobile IAB-DU cells) can be populated/updated with the new values/codes.

In some embodiments, when a mlAB changes its parent/donor IAB node (i.e., positions A->B and positions C->D of Fig. 2), the mlAB acquires the new area code from the parent/donor IAB node when performing the switching. In such a case, how the mlAB acquires the new area code from the new parent/donor IAB node may be performed with at least one (or a combination) of the following options:

A first option is for the MT part of the mlAB (mlAB-MT) to acquire the new area code via reading the MIB or SIB1 broadcast by the new parent IAB node.

A second option is for the mlAB-MT to acquire the new area code via direct RRC signalling from the new parent IAB node when performing the migration from an old parent IAB node to a new parent IAB node. In one variant of the second option, the mlAB-MT can explicitly request the new area code by sending a first RRC message to the parent/donor IAB and the parent IAB replying with a second message that includes the new area code. In another variant of the second option, the parent/donor IAB, after the mlAB-MT has just performed the access, can directly send the new area code without the mlAB-MT needing to ask for it.

A third option is for the DU part of the mlAB (mlAB-DU), when changing donor I AB(-CU), to acquire the new area code via F1 AP signalling. In one variant of the third option, the mlAB-DU can explicitly request the new area code by sending a first F1 AP message to the donor lAB(-CU), and the donor I AB(-CU) replies with a second message that includes the new area code. In another variant of the third option, the donor I AB(-CU) can directly send the new area code without the mlAB-DU asking for it.

In other embodiments, every time that a mlAB acquires a new area code, it changes the area code "to be used” with the new one received. At the same time, the mlAB will also keep a mapping between the area code and the parent/donor IAB node associated with it. In this case, if the mlAB recognises the parent/donor IAB to which it is going to do the migration (because it was previously connected to it), there is no need for the mobile IAB to request any area code from this parent/donor IAB, but it can simply start to use the one that is saved in this mapping.

In a variant of these embodiments, the mlAB may anyway ask for the area code from the parent/donor IAB to which the migration will be performed. This may be justified by the fact that the parent/donor IAB node may be also a mlAB, and may also change its area code over time. In this case, the mlAB may understand that every time that a migration is performed toward that parent/donor IAB node, the area code should be requested in any case since it may be different from the last time. On the other hand, if the area code of a certain parent/donor IAB node does not change over time, the mlAB may refrain from asking for the area code when performing the migration to that given parent/donor IAB node.

In some embodiments, the mlAB can be configured upfront (i.e. in advance) with a range of area codes to be used when connecting to a certain parent/donor IAB node. The mapping between the area code and the parent IAB may be provided by the serving CU, or by the core network via the F1 and/or NG interface, or via OAM. In one variant of these embodiments, if the mapping is configured by the serving donor CU, the serving donor CU may contact, via the XnAP interface, all the CUs (NG-RAN nodes) that it can reach in order to acquire their area codes. After collecting all the area code from neighbour CUs, the serving donor CU will build a mapping and share it with the mlAB. In another variant, the mapping can also be known (since the mobility of the mobile IAB can be considered deterministic), and thus this mapping can be provided by OAM.

In other embodiments, a dedicated area code or a list of area codes (different from the one used by the parent IAB node or donor IAB node) can be configured for the mlAB. This basically means that the mlAB will not inherit the area code of the parent IAB node or donor IAB node, but will get its own one. In one variant of these embodiments, the dedicated area code for the mlAB may cover an area that may include one or more parent lABs to which the mlAB is currently connected. In another variant of these embodiments, the dedicated area code for the mlAB may cover an area that is larger than the one covered by the donor IAB in which the mlAB is currently connected. In another variant of these embodiments, the dedicated area code for the mlAB may cover an area that is as large as the one covered by the donor IAB in which the mlAB is currently connected. In another variant, the dedicated area code for the mlAB may cover an area that is as large as the overall area in which the vehicle in which the mlAB is mounted will travel. This area may include several parent IAB nodes but also several donor IAB nodes. According to these embodiments, the mlAB may send regular updates about which area code is currently being used (if a list of area codes is configured at the mlAB) to the donor CU (or the parent IAB). These updates may be periodic (e.g. based on a timer) or even triggered (e.g. every time that a parent IAB or donor IAB node is changed), or may be explicitly requested by the parent IAB node or donor IAB node. In other embodiments, every time that the area code is changed, the mlAB may share the new area code (or a list of area codes) with the UEs that are served by the mlAB (or that are inside the vehicle in which the mlAB is mounted). The mlAB may share the new area code with the UEs via system information (e.g. via broadcast), or via dedicated RRC signalling. In case the mlAB shares a list of area codes with the UEs that it is serving, the mlAB may also indicate the area code that is currently being used (this indication can be separate from the list of area codes).

In some embodiments, if a new area code is shared by the mlAB with the UEs that it is serving, the mlAB may send, together with the new area code, an indication of whether the UEs should perform (or not) the tracking area update procedure or the RAN area update procedure. This indication can be an explicit indication such as a single field, bit or structure in message/signalling sent to the UEs that indicates that the tracking area or RAN area update procedure should be performed (or should not be performed). Alternatively, this indication can be an implicit indication meaning that if the UEs receive a new area code that is different from the previous one while still being served by the same mlAB, then the UEs should not perform the tracking area or RAN area update procedure. In one variant of these embodiments, when receiving a new area code from the same mlAB (meaning that the mlAB has not changed), the UE may not trigger any tracking area or RAN area update procedure until the UE leaves the vehicle in which the mobile IAB is mounted. In another variant, the UE may perform the tracking area or RAN area update procedure if it receives a tracking area code (TAG) or RAN area code (RANAC) (in SIB or via dedicated RRC signalling) that is not in the list of preconfigured area codes received previously by the mobile IAB.

An example flow chart/sequence diagram according to some of the above embodiments is provided in Fig. 3. Thus, Fig. 3 shows the signalling between a UE, a Mobile IAB, a Serving Cell (i.e. an IAB parent/donor, e.g. IAB parent 1 or donor X) and a Target Cell (e.g. another IAB parent/donor, e.g. IAB parent 2 or donor IAB Y). The mobile IAB acquires a SIB from the Serving Cell. The UE extracts the tracking area code (TAG) and/or RAN Notification Area (RNA) code from the SIB, and populates its own SIB content with the appropriate area code(s). The Mobile lAB's own SIB content is to be broadcast by the Mobile IAB to any UEs it is serving. The Mobile IAB then broadcasts its SIB.

When the Mobile IAB hands over to the Target Cell, which can be idle/inactive mode mobility or a connected mode handover, the Mobile IAB acquires the SIB for the Target Cell. The UE extracts the tracking area code (TAG) and/or RAN Notification Area (RNA) code from the Target Cell's SIB, and determines if the TAG and/or RNA code has changed. If the TAG and/or RNA code has changed, the UE updates the content of the SIB it broadcasts, and broadcasts the updated SIB.

Specific Rules for UEs

One drawback of having a dynamic (changing) TA and/or RAN area for a mobile IAB is that all the UEs inside the vehicle may perform a tracking area update procedure when the TA changes.

However, one observation is that even when TA has changed as shown in Fig. 4; the serving cell ID is still the same for the mobile IAB scenario; i.e. the serving cell has not changed. In such a case, a rule can be applied where a UE that realises that it is in a mobile IAB cell (for example the TA has changed but the serving cell is still the same), the UE may avoid performing a tracking area update procedure so that a ‘signalling storm' or random access channel (RACH) access from the same cell can be avoided. This rule can be applicable if the UE has already performed registration via the mobile IAB cell and thus in this specific scenario it can avoid performing a tracking area update (TAU). The AMF may assume that the UE is still in the same cell if no TAU is received from a UE which previously sent a registration/TAU from a mobile IAB cell. Further, a TAU timer specific to the mobile IAB cell can also be used, which can be longer than the usual timer, thus avoiding frequent TAUs. The registration/TAU procedure performed by the mobile IAB-MT can be deemed sufficient; i.e. the AMF can identify where the mobile IAB-MT is currently hosted (serving cell) and implicitly determine where the UE is. This is mainly for paging purposes from the AMF's perspective.

Fig. 5 is a flow chart illustrating another method according to various embodiments performed by a UE (e.g. the UE 712 or UE 800 as described later with reference to Figs. 7 and 8 respectively). The UE may perform the method in response to executing suitably formulated computer readable code. The computer readable code may be embodied or stored on a computer readable medium, such as a memory chip, optical disc, or other storage medium. The computer readable medium may be part of a computer program product.

In step 501 , the UE receives one or more area codes. The area code(s) is/are received from a vehicle-mounted network node that is serving the UE. The vehicle-mounted network node can be a mobile IAB node. The one or more area codes can comprise a code for a tracking area, a Tracking Area Code (TAG), a code for a RAN area, and/or a RAN Area Code (RANAC). In some embodiments, step 501 can comprise receiving a list of a plurality of area codes. In these embodiments, the UE can further receive an indication of which area code in the list is to be used by the UE.

In some embodiments, the method further comprises receiving an indication of whether the UE is to perform an area code update procedure. This indication can be received from the vehicle-mounted network node. The received indication can be an explicit indication.

In these embodiments, if the received indication indicates that the UE is to perform the area code update procedure, the method can further comprise performing the area code update procedure using the one or more received area codes; as shown in step 503. Alternatively, if the received indication indicates that the UE is not to perform the area code update procedure, the method can further comprise the UE refraining from performing the area code update procedure.

In some embodiments, the one or more area codes received in step 501 are different to one or more area codes previously received by the UE. However, the area codes are received in step 501 and the previously received area codes were received while the UE has the same serving cell.

In some embodiments, the method further comprises the UE refraining from performing an area code update procedure if (I) the UE previously received one or more area codes from the vehicle-mounted network node, and (ii) a serving cell of the UE has not changed since receiving those previous one or more area codes.

In alternative embodiments, the method can further comprise comparing the received one or more area codes to a list of area codes previously received from the vehicle-mounted network node; and performing an area code update procedure using the one or more received area codes if the one or more received area codes are not in the previously- received list of area codes.

Fig. 6 is a flow chart illustrating another method according to various embodiments performed by a first network node. The first network node is a network node in the RAN of the communication network, and is also referred to herein as a "RAN network node”. The first network node/RAN network node in Fig. 6 may be the RAN network node 710 or RAN network node 900 as described later with reference to Fig. 7 and 9 respectively. The first network node may perform the method in response to executing suitably formulated computer readable code. The computer readable code may be embodied or stored on a computer readable medium, such as a memory chip, optical disc, or other storage medium. The computer readable medium may be part of a computer program product.

The first network node can be a mobile I AB, a mobile IAB DU, and/or a vehicle-mounted network node. The first network node is configured to provide wireless access to a communication network for one or more UEs. The first network node is also configured to have a wireless backhaul connection to the communication network via another network node.

In step 601 , the first network node receives one or more area codes. The one or more area codes are for a second network node in the communication network that the first network node has, or will have, a wireless backhaul connection to. The one or more area codes can comprise a code for a tracking area, a Tracking Area Code (TAG), a code for a RAN area, and/or a RAN Area Code (RAN AC).

The one or more area codes received in step 601 can be received in response to a request from the first network node for area codes.

The received one or more area codes may comprise area codes for a plurality of PLMNs. In this case, the first network node can select an area code for a PLMN that the first network node is associated with.

In an embodiment, the one or more area codes are received from the second network node on or after establishing the wireless backhaul connection to the second network node. In this case, the first network node previously had a wireless backhaul connection to a third network node in the communication network.

In another embodiment, the one or more area codes are received from a third network node prior to establishing the wireless backhaul connection to the second network node.

In either embodiment, the one or more area codes can be received in an information block broadcast by the second network node or the third network node, or received in dedicated signalling from the second network node or the third network node.

In the above embodiments, the second network node and/or the third network node can be non-mobile IAB nodes, e.g. the IAB parents or donor IAB shown in Fig. 2.

In some embodiments, e.g. where the first network node is a mobile IAB DU, the one or more area codes can be received from a mobile IAB MT node. In these embodiments, the first network node and the mobile IAB MT node are part of a vehicle-mounted network node. In some embodiments, the method further comprises step 603 in which the first network node broadcasts information for use by UEs to be served by the first network node. The broadcast information comprises the area code(s) received in step 601 , or a list comprising a plurality of area codes received in step 601. In some further embodiments, the first network node can send an indication of whether the UE (that is, or that is to be, served by the first network node) is to perform an area code update procedure. The indication can be an explicit indication.

If the broadcast information comprises a list of area codes, step 603 can further comprise sending an indication of which area code in the list is to be used by the UE.

The first network node may compare the received area code(s) to one or more area codes previously received from a network node in the communication network. If the one or more area codes are different, the method further comprises step 603 in which the first network node broadcasts information for use by UEs to be served by the first network node. The broadcast information comprises the one or more area codes received in step 601 . If the one or more area codes are the same, in step 603 the first network node broadcasts information for use by UEs to be served by the first network node, with the broadcast information comprising the one or more newly- or previously-received area codes.

In some embodiments, the first network node can be configured with a list of one or more area codes to use when connected to specific network nodes. The specific network nodes relate to a route to be taken by the first network node when mounted in a vehicle. For example, the specific network nodes can be positioned near to, or otherwise provide coverage over, a scheduled or planned route to be taken by the first network node.

In some embodiments, the first network node can be configured with one or more dedicated area codes to be used by the first network node. In these embodiments, the first network node can send an update to a network node in the communication network indicating the one or more dedicated area codes being used by the first network node.

Fig. 7 shows an example of a communication system 700 in accordance with some embodiments. In the example, the communication system 700 includes a telecommunication network 702 that includes an access network 704, such as a radio access network (RAN), and a core network 706, which includes one or more core network nodes 708. The access network 704 includes one or more access network nodes, such as access network nodes 710a and 710b (one or more of which may be generally referred to as access network nodes 710), or any other similar 3^rd Generation Partnership Project (3GPP) access node or non-3GPP access point. The access network nodes 710 facilitate direct or indirect connection of wireless devices (also referred to interchangeably herein as user equipment (UE)), such as by connecting UEs 712a, 712b, 712c, and 712d (one or more of which may be generally referred to as UEs 712) to the core network 706 over one or more wireless connections. The access network nodes 710 may be, for example, access points (APs) (e.g. radio access points), base stations (BSs) (e.g. radio base stations, Node Bs, evolved Node Bs (eNBs) and New Radio (NR) NodeBs (gNBs), distributed units (DUs), central units (CUs)).

Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 700 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. The communication system 700 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

The wireless devices/UEs 712 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with the network nodes 710 and other communication devices. Similarly, the access network nodes 710 are arranged, capable, configured, and/or operable to communicate directly or indirectly with the UEs 712 and/or with other network nodes or equipment in the telecommunication network 702 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in the telecommunication network 702.

In the depicted example, the core network 706 connects the access network nodes 710 to one or more hosts, such as host 716. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 706 includes one more core network nodes (e.g. core network node 708) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the wireless devices/UEs, access network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 708. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

The host 716 may be under the ownership or control of a service provider other than an operator or provider of the access network 704 and/or the telecommunication network 702, and may be operated by the service provider or on behalf of the service provider. The host 716 may host a variety of applications to provide one or more services. Examples of such applications include the provision of live and/or pre-recorded audio/video content, data collection services, for example, retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

As a whole, the communication system 700 of Fig. 7 enables connectivity between the wireless devices/UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g. 6^th Generation (6G)); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LIFI, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

In some examples, the telecommunication network 702 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 702 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 702. For example, the telecommunications network 702 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

In some examples, the UEs 712 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 704 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 704. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

In the example illustrated in Fig. 7, the hub 714 communicates with the access network 704 to facilitate indirect communication between one or more UEs (e.g. UE 712c and/or 712d) and access network nodes (e.g. access network node 710b). In particular, the hub 714 may be a node that can operate as an IAB node, i.e. to allow/provide wireless access to UEs 712, while also backhauling traffic to other nodes, e.g. network node 710B. In this case, the hub/IAB node 714 is part of the access network 704. In other examples, the hub 714 may be a controller, router, a content source and analytics node, or any of the other communication devices described herein regarding UEs. In other examples, the hub 714 may be a broadband router enabling access to the core network 706 for the UEs. As another example, the hub 714 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 710, or by executable code, script, process, or other instructions in the hub 714. As another example, the hub 714 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 714 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 714 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 714 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, the hub 714 acts as a proxy server or orchestrator for the UEs, in particular in if one or more of the UEs are low energy loT devices.

The hub 714 may have a constant/persistent or intermittent connection to the network node 710b. The hub 714 may also allow for a different communication scheme and/or schedule between the hub 714 and UEs (e.g. UE 712c and/or 712d), and between the hub 714 and the core network 706. In other examples, the hub 714 is connected to the core network 706 and/or one or more UEs via a wired connection. Moreover, the hub 714 may be configured to connect to an M2M service provider over the access network 704 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 710 while still connected via the hub 714 via a wired or wireless connection. In some embodiments, the hub 714 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to the network node 710b. In other embodiments, the hub 714 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 710b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

Fig. 8 shows a wireless device or UE 800 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other UEs. Examples of a wireless device/UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless camera, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by the 3rd Generation Partnership Project (3GPP), including a narrow band internet of things (NB-loT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

A wireless device/UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g. a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g. a smart power meter).

The UE 800 includes processing circuitry 802 that is operatively coupled via a bus 804 to an input/output interface 806, a power source 808, a memory 810, a communication interface 812, and/or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Fig. 8. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

The processing circuitry 802 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 810. The processing circuitry 802 may be implemented as one or more hardware-implemented state machines (e.g. in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 802 may include multiple central processing units (CPUs). The processing circuitry 802 may be operable to provide, either alone or in conjunction with other UE 800 components, such as the memory 810, to provide UE 800 functionality.

In the example, the input/output interface 806 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 800. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g. a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

In some embodiments, the power source 808 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g. an electricity outlet), photovoltaic device, or power cell, may be used. The power source 808 may further include power circuitry for delivering power from the power source 808 itself, and/or an external power source, to the various parts of the UE 800 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 808. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 808 to make the power suitable for the respective components of the UE 800 to which power is supplied.

The memory 810 may be or be configured to include memory such as random access memory (RAM), readonly memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 810 includes one or more application programs 814, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 816. The memory 810 may store, for use by the UE 800, any of a variety of various operating systems or combinations of operating systems.

The memory 810 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a Universal Subscriber Identity Module (USIM) and/or Integrated Subscriber Identity Module ISIM), other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUlCC), integrated UICC (IUICC) or a removable UICC commonly known as ‘SIM card.' The memory 810 may allow the UE 800 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 810, which may be or comprise a device-readable storage medium.

The processing circuitry 802 may be configured to communicate with an access network or other network using the communication interface 812. The communication interface 812 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 822. The communication interface 812 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g. another UE or a network node in an access network). Each transceiver may include a transmitter 818 and/or a receiver 820 appropriate to provide network communications (e.g. optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 818 and receiver 820 may be coupled to one or more antennas (e.g. antenna 822) and may share circuit components, software or firmware, or alternatively be implemented separately.

In some embodiments, communication functions of the communication interface 812 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and/or standards, such as IEEE 802.11 , Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/internet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 812, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g. once every 15 minutes if it reports the sensed temperature), random (e.g. to even out the load from reporting from several sensors), in response to a triggering event (e.g. when moisture is detected an alert is sent), in response to a request (e.g. a user initiated request), or a continuous stream (e.g. a live video feed of a patient).

As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or controls a robotic arm performing a medical procedure according to the received input. A U E, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are devices which are or which are embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence on the intended application of the loT device in addition to other components as described in relation to the UE 800 shown in Fig. 8.

As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-loT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone's speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone's speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

Fig. 9 shows a network node 900 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and/or operable to communicate directly or indirectly with a UE and/or with other network nodes or equipment, in a telecommunication network. As such, network node 900 can be a network node such as access network nodes 710 in Fig. 1, or an IAB node 714 (hub 714). Examples of network nodes include, but are not limited to, access network nodes such as access points (APs) (e.g. radio access points), base stations (BSs) (e.g. radio base stations, Node Bs, evolved Node Bs (eNBs), NR NodeBs (gNBs)), vehicle-mounted network nodes, mobile IAB nodes, DUs, CUs, and IAB nodes. Network node 900 can be configured to operate as an IAB node that allows wireless access to the UEs, while also backhauling traffic to other nodes. In this case the IAB node can consist of a DU that provides access to connected UEs, and also a mobile termination (MT) that connects to other IAB nodes or donors in the uplink direction for backhaul. Network node 900 can also or alternatively be an IAB Donor, i.e. a node that provides UEs an interface to the core network and wireless functionality to other lAB-nodes to backhaul their traffic to the core network.

Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multistandard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi- cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g. Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

The network node 900 includes processing circuitry 902, a memory 904, a communication interface 906, and a power source 908, and/or any other component, or any combination thereof. The network node 900 may be composed of multiple physically separate components (e.g. a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 900 comprises multiple separate components (e.g. BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 900 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g. separate memory 904 for different RATs) and some components may be reused (e.g. a same antenna 910 may be shared by different RATs). The network node 900 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 900, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 900.

The processing circuitry 902 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 900 components, such as the memory 904, to provide network node 900 functionality. In some embodiments, the processing circuitry 902 includes a system on a chip (SOC). In some embodiments, the processing circuitry 902 includes one or more of radio frequency (RF) transceiver circuitry 912 and baseband processing circuitry 914. In some embodiments, the radio frequency (RF) transceiver circuitry 912 and the baseband processing circuitry 914 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 912 and baseband processing circuitry 914 may be on the same chip or set of chips, boards, or units.

The memory 904 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by the processing circuitry 902. The memory 904 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and/or other instructions capable of being executed by the processing circuitry 902 and utilized by the network node 900. The memory 904 may be used to store any calculations made by the processing circuitry 902 and/or any data received via the communication interface 906. In some embodiments, the processing circuitry 902 and memory 904 is integrated.

The communication interface 906 is used in wired or wireless communication of signalling and/or data between network nodes, the access network, the core network, and/or a UE. As illustrated, the communication interface 906 comprises port(s)/terminal(s) 916 to send and receive data, for example to and from a network over a wired connection.

The communication interface 906 also includes radio front-end circuitry 918 that may be coupled to, or in certain embodiments a part of, the antenna 910. Radio front-end circuitry 918 comprises filters 920 and amplifiers 922. The radio front-end circuitry 918 may be connected to an antenna 910 and processing circuitry 902. The radio front-end circuitry may be configured to condition signals communicated between antenna 910 and processing circuitry 902. The radio front-end circuitry 918 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 918 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 920 and/or amplifiers 922. The radio signal may then be transmitted via the antenna 910. Similarly, when receiving data, the antenna 910 may collect radio signals which are then converted into digital data by the radio front-end circuitry 918. The digital data may be passed to the processing circuitry 902. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, the access network node 900 does not include separate radio front-end circuitry 918, instead, the processing circuitry 902 includes radio front-end circuitry and is connected to the antenna 910. Similarly, in some embodiments, all or some of the RF transceiver circuitry 912 is part of the communication interface 906. In still other embodiments, the communication interface 906 includes one or more ports or terminals 916, the radio front-end circuitry 918, and the RF transceiver circuitry 912, as part of a radio unit (not shown), and the communication interface 906 communicates with the baseband processing circuitry 914, which is part of a digital unit (not shown).

The antenna 910 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. The antenna 910 may be coupled to the radio front-end circuitry 918 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, the antenna 910 is separate from the network node 900 and connectable to the network node 900 through an interface or port.

The antenna 910, communication interface 906, and/or the processing circuitry 902 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, the antenna 910, the communication interface 906, and/or the processing circuitry 902 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

The power source 908 provides power to the various components of network node 900 in a form suitable for the respective components (e.g. at a voltage and current level needed for each respective component). The power source 908 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 900 with power for performing the functionality described herein. For example, the network node 900 may be connectable to an external power source (e.g. the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 908. As a further example, the power source 908 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

Embodiments of the network node 900 may include additional components beyond those shown in Fig. 9 for providing certain aspects of the network node's functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, the network node 900 may include user interface equipment to allow input of information into the network node 900 and to allow output of information from the network node 900. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 900.

Fig. 10 is a block diagram illustrating a virtualization environment 1000 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1000 hosted by one or more of hardware nodes, such as a hardware computing device that operates as an access network node, a wireless device/UE, a core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g. a core network node or host), then the node may be entirely virtualized.

Applications 1002 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1000 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein.

Hardware 1004 includes processing circuitry, memory that stores software and/or instructions executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1006 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1008a and 1008b (one or more of which may be generally referred to as VMs 1008), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. The virtualization layer 1006 may present a virtual operating platform that appears like networking hardware to the VMs 1008.

The VMs 1008 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1006. Different embodiments of the instance of a virtual appliance 1002 may be implemented on one or more of VMs 1008, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, a VM 1008 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1008, and that part of hardware 1004 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1008 on top of the hardware 1004 and corresponds to the application 1002.

Hardware 1004 may be implemented in a standalone network node with generic or specific components. Hardware 1004 may implement some functions via virtualization. Alternatively, hardware 1004 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1010, which, among others, oversees lifecycle management of applications 1002. In some embodiments, hardware 1004 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signalling can be provided with the use of a control system 1012 which may alternatively be used for communication between hardware nodes and radio units.

Fig. 11 shows a communication diagram of a host 1102 communicating via a network node 1104 with a UE 1106 over a partially wireless connection in accordance with some embodiments. Example implementations, in accordance with various embodiments, of the UE (such as a UE 712a of Fig. 7 and/or UE 800 of Fig. 8), network node (such as network node 710a of Fig. 7 and/or network node 900 of Fig. 9), and host (such as host 716 of Fig. 7) discussed in the preceding paragraphs will now be described with reference to Fig. 11.

Like host QQ400, embodiments of host 1102 include hardware, such as a communication interface, processing circuitry, and memory. The host 1102 also includes software, which is stored in or accessible by the host 1102 and executable by the processing circuitry. The software includes a host application that may be operable to provide a service to a remote user, such as the UE 1106 connecting via an over-the-top (OTT) connection 1150 extending between the UE 1106 and host 1102. In providing the service to the remote user, a host application may provide user data which is transmitted using the OTT connection 1150.

The network node 1104 includes hardware enabling it to communicate with the host 1102 and UE 1106. The connection 1160 may be direct or pass through a core network (like core network 706 of Fig. 7) and/or one or more other intermediate networks, such as one or more public, private, or hosted networks. For example, an intermediate network may be a backbone network or the Internet.

The UE 1106 includes hardware and software, which is stored in or accessible by UE 1106 and executable by the UE's processing circuitry. The software includes a client application, such as a web browser or operator-specific "app” that may be operable to provide a service to a human or non-human user via UE 1106 with the support of the host 1102. In the host 1102, an executing host application may communicate with the executing client application via the OTT connection 1150 terminating at the UE 1106 and host 1102. In providing the service to the user, the UE's client application may receive request data from the host's host application and provide user data in response to the request data. The OTT connection 1150 may transfer both the request data and the user data. The UE's client application may interact with the user to generate the user data that it provides to the host application through the OTT connection 1150.

The OTT connection 1150 may extend via a connection 1160 between the host 1102 and the network node 1104 and via a wireless connection 1170 between the network node 1104 and the UE 1106 to provide the connection between the host 1102 and the UE 1106. The connection 1160 and wireless connection 1170, over which the OTT connection 1150 may be provided, have been drawn abstractly to illustrate the communication between the host 1102 and the UE 1106 via the network node 1104, without explicit reference to any intermediary devices and the precise routing of messages via these devices.

As an example of transmitting data via the OTT connection 1150, in step 1108, the host 1102 provides user data, which may be performed by executing a host application. In some embodiments, the user data is associated with a particular human user interacting with the UE 1106. In other embodiments, the user data is associated with a UE 1106 that shares data with the host 1102 without explicit human interaction. In step 1110, the host 1102 initiates a transmission carrying the user data towards the UE 1106. The host 1102 may initiate the transmission responsive to a request transmitted by the UE 1106. The request may be caused by human interaction with the UE 1106 or by operation of the client application executing on the UE 1106. The transmission may pass via the network node 1104, in accordance with the teachings of the embodiments described throughout this disclosure. Accordingly, in step 1112, the network node 1104 transmits to the UE 1106 the user data that was carried in the transmission that the host 1102 initiated, in accordance with the teachings of the embodiments described throughout this disclosure. In step 1114, the UE 1106 receives the user data carried in the transmission, which may be performed by a client application executed on the UE 1106 associated with the host application executed by the host 1102.

In some examples, the UE 1106 executes a client application which provides user data to the host 1102. The user data may be provided in reaction or response to the data received from the host 1102. Accordingly, in step 1116, the UE 1106 may provide user data, which may be performed by executing the client application. In providing the user data, the client application may further consider user input received from the user via an input/output interface of the UE 1106. Regardless of the specific manner in which the user data was provided, the UE 1106 initiates, in step 1118, transmission of the user data towards the host 1102 via the network node 1104. In step 1120, in accordance with the teachings of the embodiments described throughout this disclosure, the network node 1104 receives user data from the UE 1106 and initiates transmission of the received user data towards the host 1102. In step 1122, the host 1102 receives the user data carried in the transmission initiated by the UE 1106.

One or more of the various embodiments improve the performance of OTT services provided to the UE 1106 using the OTT connection 1150, in which the wireless connection 1170 forms the last segment. More precisely, the teachings of these embodiments may improve the UE power consumption, network load, congestion and signalling overhead and thereby provide benefits such as reduced user waiting time, better responsiveness and extended battery lifetime.

In an example scenario, factory status information may be collected and analysed by the host 1102. As another example, the host 1102 may process audio and video data which may have been retrieved from a UE for use in creating maps. As another example, the host 1102 may collect and analyse real-time data to assist in controlling vehicle congestion (e.g. controlling traffic lights). As another example, the host 1102 may store surveillance video uploaded by a UE. As another example, the host 1102 may store or control access to media content such as video, audio, VR or AR which it can broadcast, multicast or unicast to UEs. As other examples, the host 1102 may be used for energy pricing, remote control of non-time critical electrical load to balance power generation needs, location services, presentation services (such as compiling diagrams etc. from data collected from remote devices), or any other function of collecting, retrieving, storing, analysing and/or transmitting data.

In some examples, a measurement procedure may be provided for the purpose of monitoring data rate, latency and other factors on which the one or more embodiments improve. There may further be an optional network functionality for reconfiguring the OTT connection 1150 between the host 1102 and UE 1106, in response to variations in the measurement results. The measurement procedure and/or the network functionality for reconfiguring the OTT connection may be implemented in software and hardware of the host 1102 and/or UE 1106. In some embodiments, sensors (not shown) may be deployed in or in association with other devices through which the OTT connection 1150 passes; the sensors may participate in the measurement procedure by supplying values of the monitored quantities exemplified above, or supplying values of other physical quantities from which software may compute or estimate the monitored quantities. The reconfiguring of the OTT connection 1150 may include message format, retransmission settings, preferred routing etc.; the reconfiguring need not directly alter the operation of the network node 1104. Such procedures and functionalities may be known and practiced in the art. In certain embodiments, measurements may involve proprietary UE signalling that facilitates measurements of throughput, propagation times, latency and the like, by the host 1102. The measurements may be implemented in that software causes messages to be transmitted, in particular empty or 'dummy' messages, using the OTT connection 1150 while monitoring propagation times, errors, etc.

Although the computing devices described herein (e.g. UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and/or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and/or performing one or more operations based on the obtained information or converted information, and as a result of said processing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and/or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer-readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer-readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and/or by end users and a wireless network generally. The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the scope of the disclosure. Various exemplary embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

The following numbered paragraphs set out various exemplary embodiments of the techniques described herein.

Group A Embodiments

1 . A method performed by a user equipment, U E, the method comprising: receiving, from a vehicle-mounted network node that is serving the UE, one or more area codes.

2. The method of Embodiment 1 , wherein the vehicle-mounted network node is an Integrated Access and Backhaul, IAB, node.

3. The method of Embodiment 1 or 2, wherein the one or more area codes comprise a Tracking Area (TA) code and/or a Radio Access Network, RAN, Area code.

4. The method of any of Embodiments 1-3, further comprising the step of: receiving, from the vehicle-mounted network node, an indication of whether the UE is to perform an area code update procedure.

5. The method of Embodiment 4, further comprising the step of: if the received indication indicates that the UE is to perform the area code update procedure, performing the area code update procedure using the one or more received area codes; or if the received indication indicates that the UE is not to perform the area code update procedure, refraining from performing the area code update procedure.

6. The method of Embodiment 4 or 5, wherein the received indication is an explicit indication.

7. The method of any of Embodiments 1-3, further comprising the step of: refraining from performing an area code update procedure if the UE previously received one or more area codes from the vehicle-mounted network node, and a serving cell of the UE has not changed since receiving those previous one or more area codes.

8. The method of any of Embodiments 1-3, further comprising the step of: comparing the received one or more area codes to a list of area codes previously received from the vehiclemounted network node; and performing an area code update procedure using the one or more received area codes if the one or more received area codes are not in the previously-received list of area codes.

9. The method of any of Embodiments 1-8, wherein the step of receiving one or more area codes comprises receiving a list of a plurality of area codes.

10. The method of Embodiment 9, wherein the step of receiving further comprises receiving an indication of which area code in the list is to be used by the UE.

11 . The method of any of the previous embodiments, further comprising: providing user data; and forwarding the user data to a host via the transmission to the network node.

Group B Embodiments

12. A method performed by a first network node that is configured to provide wireless access to a communication network for one or more user equipments, UEs, and that is configured to have a wireless backhaul connection to the communication network via another network node, the method comprising: receiving one or more area codes, wherein the one or more area codes are for a second network node in the communication network that the first network node has, or will have, a wireless backhaul connection to.

13. The method of Embodiment 12, wherein the one or more area codes are received from the second network node on or after establishing the wireless backhaul connection to the second network node, wherein the first network node previously had a wireless backhaul connection to a third network node in the communication network.

14. The method of Embodiment 12, wherein the one or more area codes are received from a third network node prior to establishing the wireless backhaul connection to the second network node.

15. The method of Embodiment 13 or 14, wherein the one or more area codes are received in an information block broadcast by the second network node or the third network node, or received in dedicated signalling from the second network node or the third network node.

16. The method of any of Embodiments 12-15, wherein the method further comprises: comparing the received one or more area codes to one or more area codes previously received from a network node in the communication network; and if the one or more area codes are different, broadcasting information for use by UEs to be served by the first network node, the broadcast information comprising the one or more received area codes.

17. The method of any of Embodiments 12-16, wherein the one or more area codes are received in response to a request from the first network node for area codes.

18. The method of any of Embodiments 12-17, wherein the received one or more area codes comprise area codes for a plurality of Public Land Mobile Networks, PLMNs, and wherein the method further comprises: selecting an area code for a PLMN that the first network node is associated with.

19. The method of any of Embodiments 12-18, wherein the first network node is configured with a list of one or more area codes to use when connected to specific network nodes.

20. The method of Embodiment 19, wherein the specific network nodes relate to a route to be taken by the first network node when mounted in a vehicle.

21. The method of any of Embodiments 12-20, wherein the first network node is configured with one or more dedicated area codes to be used by the first network node.

22. The method of Embodiment 21, wherein the method further comprises: sending an update to a network node in the communication network indicating the one or more dedicated area codes being used by the first network node.

23. The method of any of Embodiments 12-22, wherein the method further comprises: broadcasting information for use by UEs to be served by the first network node, the broadcast information comprising the one or more received area codes.

24. The method of Embodiment 16 or 23, further comprising the step of: sending, to one or more UEs served by the first network node, an indication of whether the UE is to perform an area code update procedure.

25. The method of Embodiment 24, wherein the sent indication is an explicit indication.

26. The method of any of Embodiments 16 or 23-25, wherein the step of sending one or more area codes comprises sending a list of a plurality of area codes.

27. The method of Embodiment 26, wherein the step of sending further comprises sending an indication of which area code in the list is to be used by the UE.

28. The method of any of Embodiments 12-27, wherein the first network node is an Integrated Access and Backhaul, IAB, node.

29. The method of any of Embodiments 12-28, wherein the first network node is a vehicle-mounted network node.

30. The method of any of Embodiments 12-29, wherein the one or more area codes comprise a Tracking Area (TA) code and/or a Radio Access Network, RAN, Area code.

31 . The method of any of embodiments 12-30, further comprising: obtaining user data; and forwarding the user data to a host or a user equipment.

Group C Embodiments

32. A computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform the method of any of the Group A embodiments or the Group B embodiments.

33. A user equipment, UE, configured to perform the method of any of the Group A embodiments.

34. A user equipment, UE, comprising a processor and a memory, said memory containing instructions executable by said processor whereby said UE is operative to perform the method of any of the Group A embodiments.

35. A first network node, configured to perform the method of any of the Group B embodiments.

36. A first network node comprising a processor and a memory, said memory containing instructions executable by said processor whereby said first network node is operative to perform the method of any of the Group B embodiments.

37. A user equipment, comprising: processing circuitry configured to cause the user equipment to perform any of the steps of any of the Group A embodiments; and power supply circuitry configured to supply power to the processing circuitry.

38. A first network node, the network node comprising: processing circuitry configured to cause the network node to perform any of the steps of any of the Group B embodiments; power supply circuitry configured to supply power to the processing circuitry.

39. A user equipment (UE), the UE comprising: an antenna configured to send and receive wireless signals; radio front-end circuitry connected to the antenna and to processing circuitry, and configured to condition signals communicated between the antenna and the processing circuitry; the processing circuitry being configured to perform any of the steps of any of the Group A embodiments; an input interface connected to the processing circuitry and configured to allow input of information into the UE to be processed by the processing circuitry; an output interface connected to the processing circuitry and configured to output information from the UE that has been processed by the processing circuitry; and a battery connected to the processing circuitry and configured to supply power to the UE.

40. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to receive the user data from the host.

41 . The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data to the UE from the host.

42. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

43. A method implemented by a host operating in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the UE performs any of the operations of any of the Group A embodiments to receive the user data from the host.

44. The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

45. The method of the previous embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

46. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a cellular network for transmission to a user equipment (UE), wherein the UE comprises a communication interface and processing circuitry, the communication interface and processing circuitry of the UE being configured to perform any of the steps of any of the Group A embodiments to transmit the user data to the host.

47. The host of the previous embodiment, wherein the cellular network further includes a network node configured to communicate with the UE to transmit the user data from the UE to the host.

48. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

49. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, receiving user data transmitted to the host via the network node by the UE, wherein the UE performs any of the steps of any of the Group A embodiments to transmit the user data to the host.

50. The method of the previous embodiment, further comprising: at the host, executing a host application associated with a client application executing on the UE to receive the user data from the UE.

51 . The method of the previous embodiment, further comprising: at the host, transmitting input data to the client application executing on the UE, the input data being provided by executing the host application, wherein the user data is provided by the client application in response to the input data from the host application.

52. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to provide user data; and a network interface configured to initiate transmission of the user data to a network node in a cellular network for transmission to a user equipment (UE), the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

53. The host of the previous embodiment, wherein: the processing circuitry of the host is configured to execute a host application that provides the user data; and the UE comprises processing circuitry configured to execute a client application associated with the host application to receive the transmission of user data from the host.

54. A method implemented in a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: providing user data for the UE; and initiating a transmission carrying the user data to the UE via a cellular network comprising the network node, wherein the network node performs any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

55. The method of the previous embodiment, further comprising, at the network node, transmitting the user data provided by the host for the UE.

56. The method of any of the previous 2 embodiments, wherein the user data is provided at the host by executing a host application that interacts with a client application executing on the UE, the client application being associated with the host application.

57. A communication system configured to provide an over-the-top service, the communication system comprising: a host comprising: processing circuitry configured to provide user data for a user equipment (UE), the user data being associated with the over-the-top service; and a network interface configured to initiate transmission of the user data toward a cellular network node for transmission to the UE, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to transmit the user data from the host to the UE.

58. The communication system of the previous embodiment, further comprising: the network node; and/or the user equipment.

59. A host configured to operate in a communication system to provide an over-the-top (OTT) service, the host comprising: processing circuitry configured to initiate receipt of user data; and a network interface configured to receive the user data from a network node in a cellular network, the network node having a communication interface and processing circuitry, the processing circuitry of the network node configured to perform any of the operations of any of the Group B embodiments to receive the user data from a user equipment (UE) for the host.

60. The host of the previous 2 embodiments, wherein: the processing circuitry of the host is configured to execute a host application, thereby providing the user data; and the host application is configured to interact with a client application executing on the UE, the client application being associated with the host application.

61. The host of the any of the previous 2 embodiments, wherein the initiating receipt of the user data comprises requesting the user data.

62. A method implemented by a host configured to operate in a communication system that further includes a network node and a user equipment (UE), the method comprising: at the host, initiating receipt of user data from the UE, the user data originating from a transmission which the network node has received from the UE, wherein the network node performs any of the steps of any of the Group B embodiments to receive the user data from the UE for the host.

63. The method of the previous embodiment, further comprising at the network node, transmitting the received user data to the host.

Claims

1 . A method performed by a user equipment, U E, the method comprising: receiving (501), from a vehicle-mounted network node that is serving the UE, one or more area codes.

2. The method of claim 1 , wherein the vehicle-mounted network node is a mobile Integrated Access and Backhaul, IAB, node.

3. The method of claim 1 or 2, wherein the one or more area codes comprise a Tracking Area, TA, code and/or a Radio Access Network, RAN, Area code.

4. The method of any of claims 1-3, further comprising the step of: receiving, from the vehicle-mounted network node, an indication of whether the UE is to perform an area code update procedure.

5. The method of claim 4, further comprising the step of: if the received indication indicates that the UE is to perform the area code update procedure, performing (503) the area code update procedure using the one or more received area codes; or if the received indication indicates that the UE is not to perform the area code update procedure, refraining from performing the area code update procedure.

6. The method of claim 4 or 5, wherein the received indication is an explicit indication.

7. The method of any of claims 1-6, wherein the one or more received area codes are different to one or more previously received area codes, and wherein the one or more received area codes and previously received area codes are received while the UE has the same serving cell.

8. The method of any of claims 1-7, wherein the step of receiving (501) one or more area codes comprises receiving a list of a plurality of area codes.

9. The method of claim 8, wherein the step of receiving (501) further comprises receiving an indication of which area code in the list is to be used by the UE.

10. A method performed by a first network node that is configured to provide wireless access to a communication network for one or more user equipments, UEs, and that is configured to have a wireless backhaul connection to the communication network via another network node, the method comprising: receiving (601) one or more area codes, wherein the one or more area codes are for a second network node in the communication network that the first network node has, or will have, a wireless backhaul connection to.

11 . The method of claim 10, wherein the one or more area codes are received from the second network node on or after establishing the wireless backhaul connection to the second network node, wherein the first network node previously had a wireless backhaul connection to a third network node in the communication network.

12. The method of claim 10, wherein the one or more area codes are received from a third network node prior to establishing the wireless backhaul connection to the second network node.

13. The method of claim 11 or 12, wherein the one or more area codes are received in an information block broadcast by the second network node or the third network node, or received in dedicated signalling from the second network node or the third network node.

14. The method of any of claims 10-13, wherein the method further comprises: comparing the received one or more area codes to one or more area codes previously received from a network node in the communication network; and if the one or more area codes are different, broadcasting (603) information for use by UEs to be served by the first network node, the broadcast information comprising the one or more received area codes.

15. The method of claim 14, wherein the method further comprises: if the one or more area codes are the same, broadcasting (603) information for use by UEs to be served by the first network node, the broadcast information comprising the one or more previously received area codes.

16. The method of any of claims 10-15, wherein the one or more area codes are received in response to a request from the first network node for area codes.

17. The method of any of claims 10-16, wherein the received one or more area codes comprise area codes for a plurality of Public Land Mobile Networks, PLMNs, and wherein the method further comprises: selecting an area code for a PLMN that the first network node is associated with.

18. The method of any of claims 10-17, wherein the first network node is configured with a list of one or more area codes to use when connected to specific network nodes.

19. The method of claim 18, wherein the specific network nodes relate to a route to be taken by the first network node when mounted in a vehicle.

20. The method of any of claims 10-19, wherein the first network node is configured with one or more dedicated area codes to be used by the first network node.

21 . The method of claim 20, wherein the method further comprises: sending an update to a network node in the communication network indicating the one or more dedicated area codes being used by the first network node.

22. The method of any of claims 10-21, wherein the method further comprises: broadcasting (603) information for use by UEs to be served by the first network node, the broadcast information comprising the one or more received area codes.

23. The method of claims 16, 17 or 23, further comprising the step of: sending, to one or more UEs served by the first network node, an indication of whether the UE is to perform an area code update procedure.

24. The method of claim 24, wherein the sent indication is an explicit indication.

25. The method of any of claims 14, 15, and 22-24, wherein the step of broadcasting (603) one or more area codes comprises sending a list of a plurality of area codes.

26. The method of claim 25, wherein the step of broadcasting further comprises sending an indication of which area code in the list is to be used by the UE.

27. The method of any of claims 10-26, wherein the first network node is a mobile Integrated Access and Backhaul, IAB, node.

28. The method of any of claim 10-27, wherein the first network node is a vehicle-mounted network node.

29. The method of any of claims 10-28, wherein the first network node is a mobile Integrated Access and Backhaul, IAB, Distributed Unit, DU.

30. The method of any of claims 10-29, wherein the one or more area codes are received from a mobile Integrated Access and Backhaul, IAB, Mobile Termination, MT, node.

31. The method of any of claims 10-30, wherein the one or more area codes comprise a Tracking Area, TA, code and/or a Radio Access Network, RAN, Area code.

32. A computer program product comprising a computer readable medium having computer readable code embodied therein, the computer readable code being configured such that, on execution by a suitable computer or processor, the computer or processor is caused to perform the method of any of claims 1-31.

33. A user equipment, UE, configured to perform the method of any of claims 1-9.

34. A user equipment, UE, comprising a processor and a memory, said memory containing instructions executable by said processor whereby said UE is operative to perform the method of any of claims 1-9.

35. A first network node, configured to perform the method of any of claims 10-31 .

36. A first network node comprising a processor and a memory, said memory containing instructions executable by said processor whereby said first network node is operative to perform the method of any of claims 10-31 .